Comparative modelling of differential through-silicon vias up to 40 GHz

The three-dimensional integrated circuit has attracted considerable attention because of the evolving functions of today´s integrated circuit products and a continuing demand for reduced power consumption and miniature chip size. Through-silicon vias (TSVs) provide a vertical interconnection between stacked dies; they are much shorter and have a denser connectivity than the hybrid horizontal and bondwire interconnects in conventional use. Differential interconnects are more commonly used in high-speed digital circuits rather than single-ended ones because of their higher immunity to commonmode noise. Accordingly, presented is a scalable physical model for differential TSVs. Mixed-mode S-parameters were generated using the established model and the electrical performance of a GSSG-type differential TSV was compared with that of a GSGSG-type differential TSV. Furthermore, four-port S-parameters were measured up to 40 GHz to validate the modelled results.